HOUSTON -- Astros pitcher Alex White has spent most of the last few months throwing with rehab coordinator Daniel Roberts on the back fields at Osceola County Stadium in Kissimmee, Fla., where the only eyes on them were the occasional birds that perch atop the light towers.

Barely nine months removed from Tommy John surgery, White found himself with quite a different audience Thursday afternoon at sun-splashed Minute Maid Park, where he threw in the bullpen in front of general manager Jeff Luhnow, assistant general manager David Stearns and members of the medical staff.

White, acquired from the Rockies in December 2012, has made enough progress in rehabilitating his right elbow that he's expected to come to Spring Training in a month with little or no restrictions. He'll be battling for a spot in the bullpen or starting rotation.

"We know I'm not 100 percent yet, but for 90, 95 percent, it feels good and the ball was coming out of my hand really well," White said. "I've learned a few things with my mechanics and stuff like that in the process that will help me."

White, 25, made the Astros' Opening Day roster last year before injuring his elbow in a preseason exhibition at Minute Maid Park and getting placed on the disabled list. He underwent surgery to repair the ulnar collateral ligament in his right elbow on April 11 and has been rehabbing in Kissimmee since.

"I started throwing in early August, and it's been a process," he said. "We started at 45 feet and 25 throws, and from that day to where I am today, it seems like a giant leap. It really hasn't been, but there's been so many small steps in between we've put in, and it's been a good recovery."

White credits Roberts with keeping on track physically and even mentally, which was a challenge during the middle of the summer, when the season was in full swing and he was stuck in Kissimmee and not even throwing a baseball.

"I've heard a lot of stories about that kind of stuff," White said. "Daniel has been great with not only the physical part, but the mental part. Knowing when to take steps forward and push a little bit, when to step back and relax and let it recover. We've had a smooth recovery. I certainly don't want to jinx myself by saying that, but it's been great, the time and effort me and Daniel and [strength and conditioning coordinator] Brendan Verner have put in since April to be ready."

The isolation of the rehab process was tough at first, but it did come with some benefits.

"It really allows you to commit to the process, commit to getting better, strength-wise, and working out and throwing," White said. "That's really all you have to do, and that's really all I did down there. I committed myself to the process of getting better, and I really enjoyed it and hopefully we'll see some improvements."

The Astros' young pitching depth is led by Jarred Cosart, Brett Oberholtzer, Brad Peacock, Dallas Keuchel and Mike Foltynewicz, but White could be a sleeper. The 15th overall pick in the 2009 Draft by Cleveland, White split the 2012 season between Triple-A and the Rockies, going 2-9 with a 5.51 ERA in 23 games (20 starts).

"We do plan for him to be a part of our team this year, and I don't believe he's going to have any limitations coming to Spring Training, and that's a positive," Luhnow said. "Obviously, he made the team last year because he's a good player and good part of our future, and it was disappointing to lose him for a year, but I'll have him this year."

White says his rehab has allowed him to improve his mechanics. He's eager to get on the mound and face hitters, which could come in three to four weeks. He's a little bit ahead of schedule in terms of a typical throwing program to give him more time in between his outings.

"When we started throwing offspeed pitches, I started the process with a straight changeup, which is something I've never done," he said. "It was a rough go at first with the change. Daniel took some in the shin, but right now, it's incredible. I feel very confident in that part, and it's something that I need to add because of the disparity in velocities. I really enjoy throwing it, and I think it's going to be a good pitch for me."

Along the long road back to the mound, White picked up a little more appreciation for the game, too.

"It's a long process, and you really have to commit to it," he said. "It makes you a different person. I look at baseball a little differently now. It reminds you of how you love it and how much you want to be on the field, and that's one of the things I'll never take for granted."